The present invention is directed toward a digital odor generator or olfactometer and, more particularly, toward a digital odor generator that can be used to administer various odors alone or in various combinations to a patient or subject. The digital odor generator of the invention can also be used to administer olfactory tests remotely over the Internet or other network and to collect the results and tabulate data over such networks.
The ability to smell various odors and to distinguish odors from each other is obviously important in our every day lives. The sense of smell, which largely influences the flavor of foods, is associated with emotion, with nutrition, with quality of life, and with safety from spoiled foods, leaking natural gas, fire, and other hazardous situations. Loss of smell or the reduced ability to smell, therefore, can significantly impact everyday life. People who lose the sense of smell have major elements of their lives compromised and often become psychologically depressed.
Quantitative tests of the sense of smell can be useful as diagnostic tools. The measurement of olfactory thresholds, for example, is beneficial in the early detection and management of a number of diseases and disorders. Among these are damage to the olfactory system, such as the olfactory nerves or olfactory bulb, by head trauma, neurodegenerative diseases such as Alzheimer's disease and Parkinson's disease, acute viral and/or bacterial infections, exposure to toxic fumes and chemicals, side-effects from radiation therapy to the head, and others. A medical diagnostic instrument that can measure olfactory thresholds and other indices of olfactory function in an accurate manner, quickly and at a relatively low cost, would therefore be beneficial. Such an instrument could be used not only as a one time evaluation of a patient, but it could be used to trace a patient's progress over time to monitor for onset of a particular occurrence.
The measurement of olfactory function has been accomplished by various means. One method is by using scratch-and-sniff pads where the test operator scratches the surface to expose the odor, puts it up to the patient's nose, and asks for a response. Another test method is using squeeze-bottle or sniff bottle smell test kits. In the case of threshold testing, a series of bottles with increasing concentration of vapors is used. In most such methods the manner of stimulus presentation, which can be influenced by the test administrator, as well as the freshness of the samples, are critical factors in the test results. Obtaining good quantitative test results is frequently difficult with these methods. Another method is the use of a large research-type olfactometer. The disadvantage to this method is that the test is slow and the cost of the instrument is very high. Furthermore, the test must be administered by a trained professional.
Smaller olfactometers have been proposed and are described in various patent documents. For example, the following U.S. Patents have issued for alleged improvements to olfactometers: U.S. Pat. No. 4,265,248 to Chuiton et al.; U.S. Pat. No. 5,565,148 to Pento Fadergrass, Jr.; U.S. Pat. Nos. 6,390,453 and 6,672,129 to Frederickson et al. and U.S. Pat. No. 7,152,758 to Fazzio et al. To applicant's knowledge, none of these devices have ever been commercialized. They would appear to be either too complicated, ineffective or too expensive to produce.
Applicant is aware of an olfactometer that has become commercially available from Osmic Enterprises, Inc. of Cincinnati, Ohio, and that is alleged to be useful for assessing odor threshold, identification, discrimination, and memory. The number of odors available is limited and its design makes it difficult to change or add odors, thereby requiring that the entire machine be returned to the manufacturer if such changes need to be made. The unit also has to be returned to the manufacturer every six months for recharging. Even further, the unit utilizes a single dispensing nozzle which could cause cross contamination and thereby decrease the accuracy of the tests. This device is unable to present combinations of odors to the subject to determine how mixtures influence the overall smell sensation.
Therefore, a need exists for an olfactometer that is easy and convenient to use and maintain, which can present more than one odorant stimulus in a mixture at a time, which can allow for rapid changing of sets of odorants between subjects or patients, which can accurately present smell stimuli to subjects, and which can be used to administer smell tests remotely over the Internet or other network and subsequently collect the results and tabulate data over the Internet.